This example compares in-field ultrasonic measurements of the depths of defects in the Alaska oil pipeline to measurements of the same defects in a laboratory. The lab measurements were done in six different batches. The goal is to decide if the field measurement can be used to predict the more accurate lab measurement. In this analysis, the field measurement is the response variable and the laboratory measurement is the predictor variable. The data, in the file pipeline.txt, were given at www.itl.nist.gov/div898/handbook/pmd/section6/ -pmd621.htm. The three variables are called Field, the in-field measurement, Lab, the more accurate in-lab measurement, and Batch, the batch number.